postProcess: Stitch non-conformal couples on first time

This has required implementation of finer control of stitching in the
fvMesh read constructor and readUpdate methods. Stitching is now
controlled independently of the mesh changers. Full-geometric stitching
is now always the default unless explicitly overridden in the calls to
fvMesh's read methods.

applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoam.C

@@ -144,7 +144,11 @@ int Foam::vtkPVFoam::setTime(int nRequest, const double requestTimes[])
 
         if (meshPtr_)
         {
-            if (meshPtr_->readUpdate(false) != polyMesh::UNCHANGED)
+            if
+            (
+                meshPtr_->readUpdate(fvMesh::stitchType::nonGeometric)
+             != polyMesh::UNCHANGED
+            )
             {
                 meshChanged_ = true;
             }
@@ -474,7 +478,8 @@ void Foam::vtkPVFoam::updateFoamMesh()
                 dbPtr_(),
                 IOobject::MUST_READ
             ),
-            false
+            false,
+            fvMesh::stitchType::nonGeometric
         );
 
         meshChanged_ = true;